A beggar one day asked a philosopher for alms. The philosoper refused and went on his way. But the beggar was persistent and pursued him, loudly demanding money. He pursued him right out of the city, until at last the philosopher stopped in exasperation.
"All right, I'll give you money. But on one condition. One of my eyes is a glass eye. Tell me which eye it is and you shall have all I possess."
The beggar looked at him intently, and at length said:"Your right eye, Master, is the glass eye."
The philosopher was astonished. "Tell me how you knew. That eye was made by the greatest craftsman in the world — it should be impossible to tell it from a real eye. How did you know that my right eye was the glass one?"
"Because, Master, your right eye was the one that had a compassionate look in it."